A massively multiplayer online (MMO) game is capable of supporting thousands of players simultaneously. Typically, such games involve video. A social MMO game is a MMO that leverages an online social graph (or network) to make an MMO game more interesting to its players. Often social graphs are maintained by social networking websites such as Facebook or social media websites such as MySpace. But one might think of a contact list, buddy list, or another similar access control list (ACL) as also being a social graph.
Keeping players engaged in social MMO games is important to revenue generation, e.g., from the purchase of virtual goods or from third-party advertisements. If players are assigned game tasks that are too difficult for them to accomplish, players tend to become discouraged and withdraw from the game, leading to a reduction in revenue. But player attrition can also occur, if players are assigned game tasks that are too easy and become bored. Consequently, finding the “sweet spot” in terms of difficulty for game tasks continues to be an ongoing area of research and experimentation for the designers of social MMO games.